INDEX. 



855 



Obolus, sp. undt. f— Continued. 



general geographic and stratigraphic distribution tab- 

 ulated 100 



type specimen figured PI. XV, fig. 9 



sp. undt. g, described 423 



general geograpbic and stratigraphic distribution 



tabulated 100 



type specimen not figured. 

 06o^«5 conglomerate, in generalized section for Russia, listing 



species and localities 144 



mentioned 419 



Obolus conglomerate (Upper Cambrian), localities from sandstone 



below 395ni-r 



Obolus conglomerate (Upper Cambrian), localities in 9e, 



3361, 3901. 395f-l, 395s-u 

 Obolus sandstone (Upper Cambrian), in generalized section for 



Russia, listing species and localities 143 



in generalized section for Sweden, Denmark, Finland, and 



Norway, listing species and localities 145 



localities in 9d, 310n, 311v, 311wi 



321, 321a-d, 321o, 336a-c, 336j-m, 336r-u, 395, 395a-e, 395z 



mentioned 390, 391, 40S, 413 



Obolus (Acritis), described 437 



characterized 377 



classification of. 321, 323 



compared with ^^Euobolus," "Schmidtia," and " Thy- ' 



sanotos" by Mickwltz 434 



evolution of 317 



general geographic and stratigraphic distribution of 



the species referred to 101 



general stratigraphic distribution and number of Cam- 

 brian species and varieties of 110 



mentioned 427, 441 



number of species of, in different types of sediment . . . 160 



stratigraphic range mentioned 379 



surface ornamentation discussed 301 



type species " Obolus (Lucina) antiguisstmus " 377,437 



antiquissimus, described 437 



compared with Obolus obscurus 407 



Obolus {Acritis?) rugatus 441 



Obolus (Mickwitzella) siluricus 435,436 



Obolus (Pal^obolus) , 426 



Obolus iPaJsEobolus) bretoncTisis 427 



" Obolus ( Thysanotos) siluricus " 377-378 



general geographic and stratigraphic distribution 



tabulated 101 



type specimen not figured. 



rugatus, described 441 



compared with Obolus obscurus 407 



evolution discussed 318 



general geographic and stratigraphic distribution tab- 

 ulated 101 



type specimen figured PI. XIII, fig. 2 



Obolus (Brdggeria), described 424 



characterized 377 



classification of 321, 323 



evolution discussed 318 



evolution of 317 



general geographic and stratigraphic distribution of 



the species referred to 101 



general stratigraphic distribution and number of Cam- 

 brian species and varieties of 110 



number of species of, in different types of sediment... 160 



stratigraphic range mentioned 379 



type species "Obolella salteri" 377,424 



salteri, described 424 



compared with Obolus sp. undt. a 422 



general geographic and stratigraphic distribution tab- 

 ulated 101 



type specimen figured PI. XV, fig. 4 



" Obolus ( Eoobolus) discus," discussed 536 



figured 536 



''Obolus (Euobolus)," species and varieties recognized by Mick- 



witz, listed 3S0 



Obolus ( Fordinia), described 428 



characterized 378 



classification of. 310, 321, 323 



development 310 



evolution discussed 318 



evolution of 317 



Obolus (Fordinia)— Coiitmue6. 



general geographic and stratigraphic distribution of 



the species referred to 101 



general stratigraphic distribution and number of Cam- 

 brian species and varieties of 110 



intermediate between Obolus and Elkania 428 



muscle scars discussed 312 



number of species of, in different types of sediment... I'd?) 



stratigraphic range mentioned 379 



type species Obolus ( Fordinia) perfectus 378, 428 



bellulus, described : 428 



compared with Obolus apollinis 562 



Obolus ( Fordinia) gilberti 428, 429 



Obolus ( Fordinia) perfectus 428, 430 



general geographic and stratigraphic distribution tab- 

 ulated 101 



platform mentioned 310 



type specimen figured PI. LI, fig. 3d 



gilberti, described 429 



compared with Obolus ( Fordinia) bellulus 428, 429 



Obolus ( Fordinia) perfectus 42S, 430 



confused with Dicellomus politus - 429 ■ 



general geographic and stratigraphic distribution 



tabulated 101 



platform mentioned 310 



type specimen figured PI. LI, fig. 5 



'perfectus, described 429 



compared with Lingulella clarkei 485 



Obolus ( Fordinia) bellulus 428 



Obolus (Fordinia) gilberti 428,429 



development of 310 



general geographic- and stratigraphic distribution 



tanulated 101 



intermediate between Obolus apollinus and Elkania 



desiderata 310 



muscle scars in, discussed 310 



platform discussed 310 



tj^pe of Obolus ( Fordinia) 378, 428 



type specimen figured PI. LXIII, fig. 10a 



" Obolus (Leptembolon) lingulseformis, " type of Lingulella (Leptem- 



bolon) 474 



" Obolus (Lingulella) bicensis, " discussed 605 



Obolus (Lingulobolus), described 430 



characteri?;ed 378 



classification of 321, 323 



compared with Lingulella 432, 472 



Obolus 433,434 



evolution discussed 318 



evolution of 317 



general geographic and stratigraphic distribution of 



the species referred to loi 



mentioned 379, 471 



number of Ordovician species and varieties of 113 



number of species of, in different types of sediment. . . 160 



old-age characters discussed 315 



stratigraphic range mentioned 379 



surface ornamentation discussed 302 



type species TAmjiilella f affinis 378, 431 



affinis, described 431 



compared with Obolus feistmanteli 392 



general geographic and stratigraphic distribution 



tabulated 101 



type specimen not figured. 



spissus, described 432 



compared with A crotreta idahoensis 688 



Obolella crassa 594 



Obolus (Lingulobolus) affinis 432 



general geographic and stratigraphic distribution 



tabulated 101 



type specimen not figured. 



"Obolus (Lucina) antiquissimus ," type of Obolus (Acritis) 377,437 



Obolus ( Mickwitzella), described 434 



characterized 378 



classification 321, 323' 



compared with Obolus (Acritis) 437 



evolution discussed , — 318 



evolution of 317 



general geographic and stratigraphic distribution of 



the species referred to 101 



general stratigraphic distribution and number of 

 Cambrian species and varieties of 110 



